This man has written a lot about Kurds: http://www.amazon.co.uk/Out-Nowhere-Kurds-Syria-Peace/dp/184904435X/ref=sr_1_3?ie=UTF8&qid=1441733756&sr=8-3&keywords=kurds+syria
Same for David Romano: http://www.amazon.co.uk/Conflict-Democratization-Kurds-Middle-East/dp/1137409983/ref=sr_1_4?ie=UTF8&qid=1441733756&sr=8-4&keywords=kurds+syria
I don't know anything about this one but it seems very recent: http://www.amazon.co.uk/Kurds-Syria-Harriet-Allsopp/dp/1784533939/ref=sr_1_1?ie=UTF8&qid=1441733756&sr=8-1&keywords=kurds+syria